1. Field of the Invention
The present invention is directed to a therapy apparatus for the treatment of pathological tissue in a living subject on the basis of charging with heating radiation, whereby an ultrasound locating means for locating a region to be treated and a catheter introducible in the body of the life form, which serves the purpose of monitoring the therapy event, are provided.
2. Description of the Prior Art
In therapy apparatus, systems of the above type, the pathological tissue is heated by the heating radiation, for example microwaves or ultrasound waves. As far as the resulting temperatures lie below 45.degree. C., the cell metabolism is disturbed, with the consequence that a retardation of the growth in the case of tumors, or even an abatement of the tumor occurs. This type of treatment is referred to as local hyperthermia. When temperatures beyond 45.degree. C. are reached, the cell protein coagulates, with the result of necrotization of the tissue. This latter type of treatment is referred to as thermotherapy.
In order to avoid unintentional irradiation of healthy tissue in the case of local hyperthermia and the unintentional necrotization of healthy tissue in the case of thermotherapy, suitable measures must be undertaken. In this context, U.S. Pat. No. 4,889,122 discloses the arrangement of temperature sensors in the pathological tissue and in the environment thereof in order to be able to acquire the intensity distribution of the active ultrasound. It is also known to bring a catheter into the region of the pathological tissue in a suitable way and to monitor the resulting temperatures with a temperature sensor integrated into the catheter. Moreover, the catheter can have a coolant flowing through it in order to protect healthy tissue. Nonetheless, an unintentional irradiation or necrotization of healthy tissue cannot be reliably precluded. In particular, however, the necrotization of healthy tissue can lead to a severe injury to the patient. In the treatment, for example, of benign prostate hyperplasia (BPH), there is the risk of damage to one or both bladder sphincters. Damage to the sphincter externus leads to incontinence on the part of the patient; damage of the sphincter internus deteriorates the reproductive capability of the patient as a consequence of retrograde ejaculation.